diff options
Diffstat (limited to 'vendor/golang.org/x/tools/go/ast/astutil/enclosing.go')
| -rw-r--r-- | vendor/golang.org/x/tools/go/ast/astutil/enclosing.go | 627 |
1 files changed, 0 insertions, 627 deletions
diff --git a/vendor/golang.org/x/tools/go/ast/astutil/enclosing.go b/vendor/golang.org/x/tools/go/ast/astutil/enclosing.go deleted file mode 100644 index 6b7052b..0000000 --- a/vendor/golang.org/x/tools/go/ast/astutil/enclosing.go +++ /dev/null @@ -1,627 +0,0 @@ -// Copyright 2013 The Go Authors. All rights reserved. -// Use of this source code is governed by a BSD-style -// license that can be found in the LICENSE file. - -package astutil - -// This file defines utilities for working with source positions. - -import ( - "fmt" - "go/ast" - "go/token" - "sort" -) - -// PathEnclosingInterval returns the node that encloses the source -// interval [start, end), and all its ancestors up to the AST root. -// -// The definition of "enclosing" used by this function considers -// additional whitespace abutting a node to be enclosed by it. -// In this example: -// -// z := x + y // add them -// <-A-> -// <----B-----> -// -// the ast.BinaryExpr(+) node is considered to enclose interval B -// even though its [Pos()..End()) is actually only interval A. -// This behaviour makes user interfaces more tolerant of imperfect -// input. -// -// This function treats tokens as nodes, though they are not included -// in the result. e.g. PathEnclosingInterval("+") returns the -// enclosing ast.BinaryExpr("x + y"). -// -// If start==end, the 1-char interval following start is used instead. -// -// The 'exact' result is true if the interval contains only path[0] -// and perhaps some adjacent whitespace. It is false if the interval -// overlaps multiple children of path[0], or if it contains only -// interior whitespace of path[0]. -// In this example: -// -// z := x + y // add them -// <--C--> <---E--> -// ^ -// D -// -// intervals C, D and E are inexact. C is contained by the -// z-assignment statement, because it spans three of its children (:=, -// x, +). So too is the 1-char interval D, because it contains only -// interior whitespace of the assignment. E is considered interior -// whitespace of the BlockStmt containing the assignment. -// -// Precondition: [start, end) both lie within the same file as root. -// TODO(adonovan): return (nil, false) in this case and remove precond. -// Requires FileSet; see loader.tokenFileContainsPos. -// -// Postcondition: path is never nil; it always contains at least 'root'. -// -func PathEnclosingInterval(root *ast.File, start, end token.Pos) (path []ast.Node, exact bool) { - // fmt.Printf("EnclosingInterval %d %d\n", start, end) // debugging - - // Precondition: node.[Pos..End) and adjoining whitespace contain [start, end). - var visit func(node ast.Node) bool - visit = func(node ast.Node) bool { - path = append(path, node) - - nodePos := node.Pos() - nodeEnd := node.End() - - // fmt.Printf("visit(%T, %d, %d)\n", node, nodePos, nodeEnd) // debugging - - // Intersect [start, end) with interval of node. - if start < nodePos { - start = nodePos - } - if end > nodeEnd { - end = nodeEnd - } - - // Find sole child that contains [start, end). - children := childrenOf(node) - l := len(children) - for i, child := range children { - // [childPos, childEnd) is unaugmented interval of child. - childPos := child.Pos() - childEnd := child.End() - - // [augPos, augEnd) is whitespace-augmented interval of child. - augPos := childPos - augEnd := childEnd - if i > 0 { - augPos = children[i-1].End() // start of preceding whitespace - } - if i < l-1 { - nextChildPos := children[i+1].Pos() - // Does [start, end) lie between child and next child? - if start >= augEnd && end <= nextChildPos { - return false // inexact match - } - augEnd = nextChildPos // end of following whitespace - } - - // fmt.Printf("\tchild %d: [%d..%d)\tcontains interval [%d..%d)?\n", - // i, augPos, augEnd, start, end) // debugging - - // Does augmented child strictly contain [start, end)? - if augPos <= start && end <= augEnd { - _, isToken := child.(tokenNode) - return isToken || visit(child) - } - - // Does [start, end) overlap multiple children? - // i.e. left-augmented child contains start - // but LR-augmented child does not contain end. - if start < childEnd && end > augEnd { - break - } - } - - // No single child contained [start, end), - // so node is the result. Is it exact? - - // (It's tempting to put this condition before the - // child loop, but it gives the wrong result in the - // case where a node (e.g. ExprStmt) and its sole - // child have equal intervals.) - if start == nodePos && end == nodeEnd { - return true // exact match - } - - return false // inexact: overlaps multiple children - } - - if start > end { - start, end = end, start - } - - if start < root.End() && end > root.Pos() { - if start == end { - end = start + 1 // empty interval => interval of size 1 - } - exact = visit(root) - - // Reverse the path: - for i, l := 0, len(path); i < l/2; i++ { - path[i], path[l-1-i] = path[l-1-i], path[i] - } - } else { - // Selection lies within whitespace preceding the - // first (or following the last) declaration in the file. - // The result nonetheless always includes the ast.File. - path = append(path, root) - } - - return -} - -// tokenNode is a dummy implementation of ast.Node for a single token. -// They are used transiently by PathEnclosingInterval but never escape -// this package. -// -type tokenNode struct { - pos token.Pos - end token.Pos -} - -func (n tokenNode) Pos() token.Pos { - return n.pos -} - -func (n tokenNode) End() token.Pos { - return n.end -} - -func tok(pos token.Pos, len int) ast.Node { - return tokenNode{pos, pos + token.Pos(len)} -} - -// childrenOf returns the direct non-nil children of ast.Node n. -// It may include fake ast.Node implementations for bare tokens. -// it is not safe to call (e.g.) ast.Walk on such nodes. -// -func childrenOf(n ast.Node) []ast.Node { - var children []ast.Node - - // First add nodes for all true subtrees. - ast.Inspect(n, func(node ast.Node) bool { - if node == n { // push n - return true // recur - } - if node != nil { // push child - children = append(children, node) - } - return false // no recursion - }) - - // Then add fake Nodes for bare tokens. - switch n := n.(type) { - case *ast.ArrayType: - children = append(children, - tok(n.Lbrack, len("[")), - tok(n.Elt.End(), len("]"))) - - case *ast.AssignStmt: - children = append(children, - tok(n.TokPos, len(n.Tok.String()))) - - case *ast.BasicLit: - children = append(children, - tok(n.ValuePos, len(n.Value))) - - case *ast.BinaryExpr: - children = append(children, tok(n.OpPos, len(n.Op.String()))) - - case *ast.BlockStmt: - children = append(children, - tok(n.Lbrace, len("{")), - tok(n.Rbrace, len("}"))) - - case *ast.BranchStmt: - children = append(children, - tok(n.TokPos, len(n.Tok.String()))) - - case *ast.CallExpr: - children = append(children, - tok(n.Lparen, len("(")), - tok(n.Rparen, len(")"))) - if n.Ellipsis != 0 { - children = append(children, tok(n.Ellipsis, len("..."))) - } - - case *ast.CaseClause: - if n.List == nil { - children = append(children, - tok(n.Case, len("default"))) - } else { - children = append(children, - tok(n.Case, len("case"))) - } - children = append(children, tok(n.Colon, len(":"))) - - case *ast.ChanType: - switch n.Dir { - case ast.RECV: - children = append(children, tok(n.Begin, len("<-chan"))) - case ast.SEND: - children = append(children, tok(n.Begin, len("chan<-"))) - case ast.RECV | ast.SEND: - children = append(children, tok(n.Begin, len("chan"))) - } - - case *ast.CommClause: - if n.Comm == nil { - children = append(children, - tok(n.Case, len("default"))) - } else { - children = append(children, - tok(n.Case, len("case"))) - } - children = append(children, tok(n.Colon, len(":"))) - - case *ast.Comment: - // nop - - case *ast.CommentGroup: - // nop - - case *ast.CompositeLit: - children = append(children, - tok(n.Lbrace, len("{")), - tok(n.Rbrace, len("{"))) - - case *ast.DeclStmt: - // nop - - case *ast.DeferStmt: - children = append(children, - tok(n.Defer, len("defer"))) - - case *ast.Ellipsis: - children = append(children, - tok(n.Ellipsis, len("..."))) - - case *ast.EmptyStmt: - // nop - - case *ast.ExprStmt: - // nop - - case *ast.Field: - // TODO(adonovan): Field.{Doc,Comment,Tag}? - - case *ast.FieldList: - children = append(children, - tok(n.Opening, len("(")), - tok(n.Closing, len(")"))) - - case *ast.File: - // TODO test: Doc - children = append(children, - tok(n.Package, len("package"))) - - case *ast.ForStmt: - children = append(children, - tok(n.For, len("for"))) - - case *ast.FuncDecl: - // TODO(adonovan): FuncDecl.Comment? - - // Uniquely, FuncDecl breaks the invariant that - // preorder traversal yields tokens in lexical order: - // in fact, FuncDecl.Recv precedes FuncDecl.Type.Func. - // - // As a workaround, we inline the case for FuncType - // here and order things correctly. - // - children = nil // discard ast.Walk(FuncDecl) info subtrees - children = append(children, tok(n.Type.Func, len("func"))) - if n.Recv != nil { - children = append(children, n.Recv) - } - children = append(children, n.Name) - if n.Type.Params != nil { - children = append(children, n.Type.Params) - } - if n.Type.Results != nil { - children = append(children, n.Type.Results) - } - if n.Body != nil { - children = append(children, n.Body) - } - - case *ast.FuncLit: - // nop - - case *ast.FuncType: - if n.Func != 0 { - children = append(children, - tok(n.Func, len("func"))) - } - - case *ast.GenDecl: - children = append(children, - tok(n.TokPos, len(n.Tok.String()))) - if n.Lparen != 0 { - children = append(children, - tok(n.Lparen, len("(")), - tok(n.Rparen, len(")"))) - } - - case *ast.GoStmt: - children = append(children, - tok(n.Go, len("go"))) - - case *ast.Ident: - children = append(children, - tok(n.NamePos, len(n.Name))) - - case *ast.IfStmt: - children = append(children, - tok(n.If, len("if"))) - - case *ast.ImportSpec: - // TODO(adonovan): ImportSpec.{Doc,EndPos}? - - case *ast.IncDecStmt: - children = append(children, - tok(n.TokPos, len(n.Tok.String()))) - - case *ast.IndexExpr: - children = append(children, - tok(n.Lbrack, len("{")), - tok(n.Rbrack, len("}"))) - - case *ast.InterfaceType: - children = append(children, - tok(n.Interface, len("interface"))) - - case *ast.KeyValueExpr: - children = append(children, - tok(n.Colon, len(":"))) - - case *ast.LabeledStmt: - children = append(children, - tok(n.Colon, len(":"))) - - case *ast.MapType: - children = append(children, - tok(n.Map, len("map"))) - - case *ast.ParenExpr: - children = append(children, - tok(n.Lparen, len("(")), - tok(n.Rparen, len(")"))) - - case *ast.RangeStmt: - children = append(children, - tok(n.For, len("for")), - tok(n.TokPos, len(n.Tok.String()))) - - case *ast.ReturnStmt: - children = append(children, - tok(n.Return, len("return"))) - - case *ast.SelectStmt: - children = append(children, - tok(n.Select, len("select"))) - - case *ast.SelectorExpr: - // nop - - case *ast.SendStmt: - children = append(children, - tok(n.Arrow, len("<-"))) - - case *ast.SliceExpr: - children = append(children, - tok(n.Lbrack, len("[")), - tok(n.Rbrack, len("]"))) - - case *ast.StarExpr: - children = append(children, tok(n.Star, len("*"))) - - case *ast.StructType: - children = append(children, tok(n.Struct, len("struct"))) - - case *ast.SwitchStmt: - children = append(children, tok(n.Switch, len("switch"))) - - case *ast.TypeAssertExpr: - children = append(children, - tok(n.Lparen-1, len(".")), - tok(n.Lparen, len("(")), - tok(n.Rparen, len(")"))) - - case *ast.TypeSpec: - // TODO(adonovan): TypeSpec.{Doc,Comment}? - - case *ast.TypeSwitchStmt: - children = append(children, tok(n.Switch, len("switch"))) - - case *ast.UnaryExpr: - children = append(children, tok(n.OpPos, len(n.Op.String()))) - - case *ast.ValueSpec: - // TODO(adonovan): ValueSpec.{Doc,Comment}? - - case *ast.BadDecl, *ast.BadExpr, *ast.BadStmt: - // nop - } - - // TODO(adonovan): opt: merge the logic of ast.Inspect() into - // the switch above so we can make interleaved callbacks for - // both Nodes and Tokens in the right order and avoid the need - // to sort. - sort.Sort(byPos(children)) - - return children -} - -type byPos []ast.Node - -func (sl byPos) Len() int { - return len(sl) -} -func (sl byPos) Less(i, j int) bool { - return sl[i].Pos() < sl[j].Pos() -} -func (sl byPos) Swap(i, j int) { - sl[i], sl[j] = sl[j], sl[i] -} - -// NodeDescription returns a description of the concrete type of n suitable -// for a user interface. -// -// TODO(adonovan): in some cases (e.g. Field, FieldList, Ident, -// StarExpr) we could be much more specific given the path to the AST -// root. Perhaps we should do that. -// -func NodeDescription(n ast.Node) string { - switch n := n.(type) { - case *ast.ArrayType: - return "array type" - case *ast.AssignStmt: - return "assignment" - case *ast.BadDecl: - return "bad declaration" - case *ast.BadExpr: - return "bad expression" - case *ast.BadStmt: - return "bad statement" - case *ast.BasicLit: - return "basic literal" - case *ast.BinaryExpr: - return fmt.Sprintf("binary %s operation", n.Op) - case *ast.BlockStmt: - return "block" - case *ast.BranchStmt: - switch n.Tok { - case token.BREAK: - return "break statement" - case token.CONTINUE: - return "continue statement" - case token.GOTO: - return "goto statement" - case token.FALLTHROUGH: - return "fall-through statement" - } - case *ast.CallExpr: - if len(n.Args) == 1 && !n.Ellipsis.IsValid() { - return "function call (or conversion)" - } - return "function call" - case *ast.CaseClause: - return "case clause" - case *ast.ChanType: - return "channel type" - case *ast.CommClause: - return "communication clause" - case *ast.Comment: - return "comment" - case *ast.CommentGroup: - return "comment group" - case *ast.CompositeLit: - return "composite literal" - case *ast.DeclStmt: - return NodeDescription(n.Decl) + " statement" - case *ast.DeferStmt: - return "defer statement" - case *ast.Ellipsis: - return "ellipsis" - case *ast.EmptyStmt: - return "empty statement" - case *ast.ExprStmt: - return "expression statement" - case *ast.Field: - // Can be any of these: - // struct {x, y int} -- struct field(s) - // struct {T} -- anon struct field - // interface {I} -- interface embedding - // interface {f()} -- interface method - // func (A) func(B) C -- receiver, param(s), result(s) - return "field/method/parameter" - case *ast.FieldList: - return "field/method/parameter list" - case *ast.File: - return "source file" - case *ast.ForStmt: - return "for loop" - case *ast.FuncDecl: - return "function declaration" - case *ast.FuncLit: - return "function literal" - case *ast.FuncType: - return "function type" - case *ast.GenDecl: - switch n.Tok { - case token.IMPORT: - return "import declaration" - case token.CONST: - return "constant declaration" - case token.TYPE: - return "type declaration" - case token.VAR: - return "variable declaration" - } - case *ast.GoStmt: - return "go statement" - case *ast.Ident: - return "identifier" - case *ast.IfStmt: - return "if statement" - case *ast.ImportSpec: - return "import specification" - case *ast.IncDecStmt: - if n.Tok == token.INC { - return "increment statement" - } - return "decrement statement" - case *ast.IndexExpr: - return "index expression" - case *ast.InterfaceType: - return "interface type" - case *ast.KeyValueExpr: - return "key/value association" - case *ast.LabeledStmt: - return "statement label" - case *ast.MapType: - return "map type" - case *ast.Package: - return "package" - case *ast.ParenExpr: - return "parenthesized " + NodeDescription(n.X) - case *ast.RangeStmt: - return "range loop" - case *ast.ReturnStmt: - return "return statement" - case *ast.SelectStmt: - return "select statement" - case *ast.SelectorExpr: - return "selector" - case *ast.SendStmt: - return "channel send" - case *ast.SliceExpr: - return "slice expression" - case *ast.StarExpr: - return "*-operation" // load/store expr or pointer type - case *ast.StructType: - return "struct type" - case *ast.SwitchStmt: - return "switch statement" - case *ast.TypeAssertExpr: - return "type assertion" - case *ast.TypeSpec: - return "type specification" - case *ast.TypeSwitchStmt: - return "type switch" - case *ast.UnaryExpr: - return fmt.Sprintf("unary %s operation", n.Op) - case *ast.ValueSpec: - return "value specification" - - } - panic(fmt.Sprintf("unexpected node type: %T", n)) -} |